The base of a conventional swivel chair comprises a plurality of legs radiating from a central hub having a pivot post extending vertically upward and supporting the chair seat at its upper end. The legs are preferably tapered to provide an aesthetic appearance and good structural design and have been made of various materials including wood and metal, the wood legs being relatively bulky in order to provide adequate strength.
Tapered tubular legs formed from sheet metal have been provided to reduce size and cost while providing adequate strength and pleasing appearane. A conventional method of making a tapered tubular leg is to start with a flat sheet metal blank tapered longitudinally with tabs at its smaller end, form flanges at 90.degree. along the outer longitudinal edges of the blank each equal in depth to one-half the thickness of the finished tube, then fold the blank through 180.degree. to form parallel tapered side walls and bring the edge flanges into edgewise abutment, seam weld the abutting edges together, and then bend the end tabs around a tubular caster-supporting bushing and weld the tabs thereto.